Protective suit having an audio transceiver

ABSTRACT

A VOICE-OPERATED RECEIVING AND TRANSMITTING SYSTEM FOR A WEARER OF A PROTECTIVE SUIT WHICH CAN BE AUTOMATICALLY CHANGED FROM A RECEIVING CONDITION TO A TRANSMITTING CONDITION RESPONSIVE TO THE WEARER&#39;&#39;S VOICE. THE SYSTEM IS PROVIDED WITH A CONTROL FOR REGULATING THE AUDIO LEVEL AT WHICH THE SWITCHING OPERATION TAKES PLACE.

United States Patent Herbert E. Cribb Satellite Beach, Fla.

Dec. 1 1, 1968 The United States of America as represented by theAdministrator of the National Aeronautics and Space Administrationinventor Appl. No. Filed Patented Assignee PROTECTIVE SUIT HAVTNG ANAUDHO TRANSCEIVER l1 Claim, 3 Drawing Figs.

US. Cl. 179/1111, l79/1VC int. C1 1804i- 11/441 FieldolfSearch1791157.],

1(VC), 1 (A), 183, 156, 1 (UW) References Cited UNITED STATES PATENTSBrody DeVito Laughlin et a1. Heitman Doddington Brody Burnett Wainwrightet al..

Primary Examiner- Kathleen H. Claffy Assistant ExaminerRandall P. MyersAttorneys-James O. Harrell and G. T, McCoy 179/1(VC) l79/1(VC) 179/157X179/156X 179/l(VC) 179/l(.4) 179/1(UW) l79/1(UW) ABSTRACT: Avoice-operated receiving and transmitting system for a wearer of aprotective sun which can be automatically changed from a receivingcondition to a transmitting condition responsive to the wearers voice.The system is provided with a control for regulating the audio level atwhich the switching operation takes place.

PATENTED JUN28 I971 SHEET 1. [1F 2 "1 l HEADPHONE I l l I I I DNSIDE. ISCAPE sun- I I I 15 I VOICE MIKE OPERATED I l AMP L f ATTORNEYS.

PROTECTIVE SUIT HAVING AN AUDIO TRANSCEIVER This invention describedherein was made by an employee of the United States Government, and maybe manufactured and used by or for the Government for Governmentalpurposes without the payment of any royalties thereon or therefor.

One of the problems encountered in wearing protective suits whichcompletely encompasses the wearers body is communicating with otherswithout directly connecting a hard-line to the suit. This isparticularly true where the suits are provided for resisting highlycorrosive substances and temperatures. Such requires suits made ofseveral layers of material, thus restricting voice communication betweenthe wearer of the suit and others. This problem also is encountered byas tronauts who wear space suits during launching and space explorationmissions.

Some suits, such as disclosed in U.S. Pat. No. 3,003,136 granted toBurnett et al., on Oct. 3, i961, and U.S. Pat. No. 3,076,174 granted toWainwright et al., on Jan. 29, 1963, are provided with a system in whichthe wearer of a suit can receive and transmit normal voicecommunication. However, one problem is that in order toswitch from thetransmitting condition to the receiving condition a switch has to bemanually operated. This mode is not practical where the wearer is usinghis hands to perform other functions.

Radio frequency type units have been tried, however, they present apossible hazard around pyrotechnic devices which can be activated by theradio frequency signal. Furthermore, radio frequency signals are onlyreceived from a particular mike and would not detect sounds remote fromthe location of that mike, Moreover, radio frequency signals are oftenjammed by external sources, such as broadcasts to emergency vehicles,taxis, airports, etc. Problems would also arise where the wearer isworking within confined areas, such as in tanks, which act as a shieldagainst the radio frequency signals.

The fact that the wearer ofa protective suit cannot communicate withother persons working with him and cannot hear noises in the immediatevicinity frequently has an adverse psychological effect on the wearer.lt is desirable to be able to hear all noises in the immediate workingvicinity so that the wearer can be alerted to dangers which may be outof his visible spectrum. lt is also desirable that when an emergencyarises to be able to communicate readily with others in the immediatevicinity without tying up the wearer's hand or being encumbered with acork or hard-line.

In accordance with the present invention, it has been found thatdifficulties encountered in the above-mentioned communicating apparatusmay be overcome by providing a novel communicating system for wearer'sof protective suits. This voice operated receiving and transmittingsystem for a wearer of protective suits includes the following basicparts: (1) a microphone carried in the suit for transmitting the wearersvoice, (2) a combination speaker and receiver provided for receivingexternal sounds and transmitting the wearer's voice externally of thesuit, (3) a headphone carried adjacent the wearer's ears forbroadcasting sounds received by the combination speaker and receiver tothe wearers ears, (4) an amplifier means for amplifying sounds passingthrough the receiving and transmitting system, (5) switching means forconnecting the amplifying means between the microphone and thecombination speaker and receiver when in a second position, and (6) avoice-operated actuating means coupled to the output ofthe microphonefor causing a switching means to be switched from the first position tothe second position responsive to the wearer speaking into themicrophone. Thus, the voice of the wearer of the protective suitautomatically switches the receiving and transmitting system from areceiving mode to the transmitting mode.

Accordingly, it is an important object of the present inven tion toprovide a voice-operated receiving and transmitting system for a wearerof a protective suit which automatically enables him to speak and hearnormal sounds, such as conversation.

Another important object of the present invention is to provide areceiving and transmitting system which can be regulated to be activatedby the human voice and not by low volume noises.

Still another important object of the present invention is to provide aprotective suit with a communication system which does not requiremanual manipulation of switches and is rugged and reliable.

Other objects and advantages of this invention will become more apparentfrom a reading of the following detailed description and appended claimstaken in conjunction with the accompanying drawings wherein:

FIG. 11 is a perspective front view illustrating a protective suitequipped with a receiving and transmitting system constructed inaccordance with the present invention,

FIG. 2 is a block diagram illustrating schematically the components ofthe receiving and transmitting system constructed in accordance with thepresent invention, and

FIG. 3 is a circuit diagram illustrating in detail certain portions ofthe receiver and transmitting system.

Referring in more detail to the drawings wherein like reference numeralsdesignate identical or corresponding parts throughout the views, andwith special attention to FIG. 1, reference numeral 10 generallydesignates a protective suit on a wearer having a head portion 11 with atransparent window therein. Headphones 12 are carried inside the headportion ill for broadcasting to the wearer signals received. Hangingaround the wearer's neck by means of a wire 13 is a combination speakerand receiver means 114 which enables the wearer of the protective suitto communicate with others in the near vicinity. The major components ofthe receiving and transmitting system are shown in the block diagramillustrated in FIG. 2 and include a microphone 15, which is positionedin the face mask of the suit adjacent the user's mouth for transmittinghis voice to a voice-operated amplifier 16. When the user desires tospeak he speaks into the microphone 15 and the normal level of his voiceis sufficient to activate the voiceoperated amplifier 16. This causes arelay 17 to be energized to pull the contacts 18 and 119 down to thebroken line position shown in FIG. 2 which allows the signal coming fromthe mike to pass through the voice amplifier 16,. line 20, terminal 2],terminal 22, lead 23, to the speaker mike preamplifier 241. This speakermike preamplifier 24 may be any conventional or suitable speaker mikepreamplifier and! it, in turn, feeds the amplified signal to a poweramplifier 25. The purpose of the speaker mike preamplifier 24 is toamplify the very weak signal produced by the microphone is andvoice-operated amplifier 16 so that the power amplifier 25 can amplifysuch further. It is noted that a battery pack 26 is provided forenergizing the voice-operated amplifier lllfi, the speaker mikepreamplifier 24, and the power amplifier 25, by means ofleads 27, 28 and20, respectively. The signal coming out of the power amplifier 25 passesthrough lead 30 to terminal 31 through contact 18, which is now in thelower position, to the combination speaker and receiver 1-4. Thecombination speaker and receiver can be any conventional speaker andreceiver which is capable of transmitting and receiving audio signals.

When the user stops speaking into the microphone 15 the relay 17 isdeenergized and the contacts 18 land 19 returned to the full line or upposition illustrated in FIG. 2. In this position the system is in thereceive condition, i.e., it will receive any audio signals above acertain predetermined level and such signals will be transmitted to theheadphone 12. Thus, when the speaker M is in the receiving state theaudio signals pass through the speaker 14, contact 19, lead 23, thespeaker mike preamplifier 24, the power amplifier 25, lead 30, contact18, lead 32, and is heard by the user through the headphones 12 locatedinside of the protective suit. There is a conventional impedancemismatch out of the power amplifier 25 feeding the headphone 12 when thesystem is in the receive position. This impedance mismatch attenuatesthe signal to a normal headphone receiving audio level. Such powermismatch is conventional in many audio devices, or circuits whichincorporate a speaker and a headphone.

From the block diagram it can be seen that when the user desires tospeak he merely speaks into the microphone and such is transmittedexternally of the protective suit by the combination speaker andreceiver 14. When he is not talking the system is in the receiveposition so that he can hear noises above a particular audio level inthe immediate vicinity. In one particular device users of the system cancommunicate at normal voice level at a distance of approximately 50feet. lt is desired that the voice-operated amplifier 16 be biased to acertain level so that such is not activated by noises inside theprotective suit, such as the hissing of air rushing into the suit, etc.This is to maintain the system in a receive condition except when theuser speaks.

Since the preamplifier 24 and the power amplifier 25 are conventionalitems, only a detailed description will be given of the voice-operatedamplifier l6 and relay 17. The audio signal produced by the user isspoken into the microphone 15 and is fed into an impedance matchingtransformer 33 which has its secondary winding coupled to the baseelectrode 34 ofa PNP- type transistor 35. The signal is coupled throughthe coupling capacitor 36 interposed in lead 37. The signal is amplifiedvia current flowing in an emitter electrode 38 and out collectorelectrode 39 and is fed to junction 40. A voltage dropping resistor 41is coupled between junction andjunction 42 interposed in lead 43. Avoltage dividing network which includes resistors 44 and 45 is connectedbetween junction 42 and junction 46 interposed in the grounded lead 47.The base electrode 34 of the transistor 35 is coupled to the junction 48intermediate the voltage dividing resistors 44 and 45, respectively. Thebiasing resistor and capacitor network, which includes resistor 49 andcapacitor 50, is interposed between the emitter electrode 38 and theground lead 47.

At junction 51 the amplified signal is divided and a portion of such isfed through lead 52, coupling capacitor 53, potentiometer 54, to lead20, which is connected to the preamplifier via lead 23 and contact 19when such is in the down position. The purpose of the potentiometer 54is to provide a means to control the level which audio signals willactivate the preamplifier so that noises inside the suit, such asproduced by the air coming into the suit, will not activate thepreamplifier.

The signal at junction 51 is also applied to the base electrode 55 ofanother PNP amplifying transistor 56 through a coupling capacitor 57interposed in lead 58 connected between the base electrode 55 and thejunction 51. The amplifier 56 amplifies the signal and feeds suchthrough a coupling capacitor 59 to the base electrode 60 of stillanother PNP amplifying transistor 61.

A voltage dividing network including resistors 62 and 63 is connectedbetween common lead 47 and lead 43, and to lead 55. The voltage droppingresistor 64 is connected between the collector electrode 65 oftransistor 56 and lead 43. Connected between the emitter electrode 66and ground lead 47 is a biasing resistor and capacitor network whichincludes resistor 67 and capacitor 68. Another voltage dividing networkwhich includes resistors 69 and 70 is connected between lead 43 andground lead 47 and is joined by lead 71 connected to base electrode 60of transistor 61. A biasing resistor capacitor network which includesresistor 72 and capacitor 73 is interposed between the emitter electrode74 and the ground lead 47. A collector electrode 75 is connected througha voltage dropping resistor 76 to lead 43.

After the signal leaves the amplifying transistor 61 it is then fedthrough a rectifying circuit generally designated by reference character77 which rectifies the signal and feeds such to junction 78. Thepotentiometer 79 is interposed between lead 43 and ground lead 47, andhas its movable contact 80 connected through resistor 81 to junction 78so that the level of the signal for controlling the energization ofrelay 17 can be set to a predetermined value. The potentiometer can beadjusted to take into consideration the fact that certain users speaklower than others.

The rectifier network 77 includes a coupling capacitor 82, interposed inlead 83, extending between the collector 75 of transistor 61 andjunction 78. Another coupling capacitor 84 is connected between junction85 and junction 86 in lead 83. A diode 87 is connected between junction86 and a junction 88 with the anode being adjacent junction 86. Parallelcircuits which include resistor 89, diode 90, and capacitor 91,respectively, are connected between junction 92 and junctions 85,

86 and 88, respectively. The anode of the diode 90 is adjacent junction92. Junction 92 is connected by means of lead 93 to junction 94 which isinterposed in lead 95 which is coupled between junctions 96 and 97.Junction 97 is, in turn, connected to lead 29 coming from the battery 26for providing a biasing voltage for the transistors 98 and 99. The NPNtransistors 98 and 99 are coupled together to amplify the current sothat such will be sufficient to activate the relay 17 when the userspeaks into the microphone 15. The signal coming into the base electrode100 of transistor 98 via resistor 101 is amplified by the substantiallyparallel arrangement of the current amplifying transistors 98 and 99 andis fed out the collector 102 of transistor 99 through the relay coil 17to the grounded lead 47. As the current flows through the relay coil 17it energizes the relay pulling down the contacts 18 and 19 to the dottedline position. In this position the voice of the user passes through thespeaker mike preamplifier, the power amplifier to the speaker receiver14 externally of the suit.

Transistors 98 and 99 are N PN transistors and the collector oftransistor 98 is coupled to the collector of transistor 99 by lead 103.The emitter 104 of transistor 98 is coupled to the base electrode 105 oftransistor 99 by lead 106.

When the user of the suit stops speaking the relay 17 is deenergizedallowing the contacts to move back to the full line position so thatexternal sounds can be picked up by the speaker-receiver 14 and heard bythe user by means of the headset 12. It is noted that when the user isspeaking through the microphone 15 the relay 17 disengages the headsetfrom the circuit via moving the contacts 18 and 19 to the broken lineposition.

In summarizing the operation, it can be seen that the user of the suitcan communicate readily with others in the immediate vicinity by merelyspeaking into the microphone 15 carried on the face mask of his headgear. As soon as he stops speaking the system returns to a receivingcondition wherein he can hear through the headset 12 sounds in theimmediate vicinity. The system is provided with means for adjusting thelevel at which the switching relay 17 is energized.

While a preferred embodiment of the invention has been described usingspecific terms, such description is for illustrative purposes only, andit is to be understood that changes and variations may be made withoutdeparting from the spirit or scope of the following claims.

lclaim:

1. A protective suit in which a wearer is completely encompassed andthereby normally unable to hear and speak externally of said suitcomprising, in combination:

A. a microphone carried inside said suit for transmitting the wearersvoice;

B. a combination speaker and receiver means located outside of said suitfor both receiving external sounds and transmitting the wearer's voiceexternally of said suit;

C. a headphone carried inside said suit adjacent the wearer's ears fortransmitting sounds received by said combination speaker and receivermeans to the wearer's ears;

D. amplifier means for amplifying sounds passing through saidcombination speaker and receiver means;

E. switching means for connecting said amplifying means betweenheadphone and said combination speaker and receiver means when in afirst position andfor connecting said amplifying means between saidmicrophone and said combination speaker and receiver means when in asecond position;

for automatically switching said switching means from said first normalposition to said second position; and

. control means coupled to said voice-operated amplifier for setting thenoise level at which said relay means is actuated to switch saidswitching means from said first normal position to said second position.

